vf_screenshot: simplify

Instead of using a callback to "capture" the image next time the filter
function is called, do it the other way around: on every filter
invocation, create a reference to the image, and return it if a
screenshot is requested. This also fixes the 1-frame delay when taking
screenshots with the filter.

This also allows simplifying screenshot.c.

1 files changed, 19 insertions, 52 deletions

diff --git a/core/screenshot.c b/core/screenshot.c
index 8e16771289..0f397f2dd7 100644
--- a/core/screenshot.c
+++ b/core/screenshot.c
@@ -48,7 +48,6 @@ typedef struct screenshot_ctx {
 
     int mode;
     int each_frame;
-    int using_vf_screenshot;
 
     int frameno;
 } screenshot_ctx;
@@ -234,16 +233,9 @@ static char *gen_fname(screenshot_ctx *ctx, const char *file_ext)
     }
 }
 
-static struct mp_image *add_subs(struct MPContext *mpctx,
-                                 struct mp_image *image)
+static void add_subs(struct MPContext *mpctx, struct mp_image *image)
 {
-    if (!(image->flags & MP_IMGFLAG_ALLOCATED)) {
-        struct mp_image *new_image = alloc_mpi(image->w, image->h,
-                                               image->imgfmt);
-        copy_mpi(new_image, image);
-        vf_clone_mpi_attributes(new_image, image);
-        image = new_image;
-    }
+    mp_image_make_writeable(image);
 
     int d_w = image->display_w ? image->display_w : image->w;
     int d_h = image->display_h ? image->display_h : image->h;
@@ -259,8 +251,6 @@ static struct mp_image *add_subs(struct MPContext *mpctx,
 
     osd_draw_on_image(mpctx->osd, res, mpctx->osd->vo_pts,
                       OSD_DRAW_SUB_ONLY, image);
-
-    return image;
 }
 
 static void screenshot_save(struct MPContext *mpctx, struct mp_image *image,
@@ -270,31 +260,18 @@ static void screenshot_save(struct MPContext *mpctx, struct mp_image *image,
 
     struct image_writer_opts *opts = mpctx->opts.screenshot_image_opts;
 
-    struct mp_image *new_image = image;
     if (with_subs)
-        new_image = add_subs(mpctx, new_image);
+        add_subs(mpctx, image);
 
     char *filename = gen_fname(ctx, image_writer_file_ext(opts));
     if (filename) {
         mp_msg(MSGT_CPLAYER, MSGL_INFO, "*** screenshot '%s' ***\n", filename);
-        if (!write_image(new_image, opts, filename))
+        if (!write_image(image, opts, filename))
             mp_msg(MSGT_CPLAYER, MSGL_ERR, "\nError writing screenshot!\n");
         talloc_free(filename);
     }
 
-    if (new_image != image)
-        free_mp_image(new_image);
-}
-
-static void vf_screenshot_callback(void *pctx, struct mp_image *image)
-{
-    struct MPContext *mpctx = (struct MPContext *)pctx;
-    screenshot_ctx *ctx = mpctx->screenshot_ctx;
-    screenshot_save(mpctx, image, ctx->mode == MODE_SUBTITLES);
-    if (ctx->each_frame) {
-        ctx->each_frame = false;
-        screenshot_request(mpctx, ctx->mode, true);
-    }
+    talloc_free(image);
 }
 
 static bool force_vf(struct MPContext *mpctx)
@@ -315,7 +292,6 @@ void screenshot_request(struct MPContext *mpctx, int mode, bool each_frame)
     if (mpctx->video_out && mpctx->video_out->config_ok) {
         screenshot_ctx *ctx = mpctx->screenshot_ctx;
 
-        ctx->using_vf_screenshot = 0;
 
         if (mode == MODE_SUBTITLES && mpctx->osd->render_subs_in_filter)
             mode = 0;
@@ -332,26 +308,24 @@ void screenshot_request(struct MPContext *mpctx, int mode, bool each_frame)
 
         struct voctrl_screenshot_args args =
                             { .full_window = (mode == MODE_FULL_WINDOW) };
-        if (!force_vf(mpctx)
-            && vo_control(mpctx->video_out, VOCTRL_SCREENSHOT, &args) == true)
-        {
+
+        if (!force_vf(mpctx))
+            vo_control(mpctx->video_out, VOCTRL_SCREENSHOT, &args);
+
+        if (!args.out_image) {
+            mp_msg(MSGT_CPLAYER, MSGL_INFO, "No VO support for taking"
+                   " screenshots, trying VFCTRL_SCREENSHOT!\n");
+            struct vf_instance *vfilter = mpctx->sh_video->vfilter;
+            vfilter->control(vfilter, VFCTRL_SCREENSHOT, &args);
+        }
+
+        if (args.out_image) {
             if (args.has_osd)
                 mode = 0;
             screenshot_save(mpctx, args.out_image, mode == MODE_SUBTITLES);
-            free_mp_image(args.out_image);
         } else {
-            mp_msg(MSGT_CPLAYER, MSGL_INFO, "No VO support for taking"
-                   " screenshots, trying VFCTRL_SCREENSHOT!\n");
-            ctx->using_vf_screenshot = 1;
-            struct vf_ctrl_screenshot cmd = {
-                .image_callback = vf_screenshot_callback,
-                .image_callback_ctx = mpctx,
-            };
-            struct vf_instance *vfilter = mpctx->sh_video->vfilter;
-            if (vfilter->control(vfilter, VFCTRL_SCREENSHOT, &cmd) !=
-                    CONTROL_OK)
-                mp_msg(MSGT_CPLAYER, MSGL_INFO,
-                       "...failed (need --vf=screenshot?)\n");
+            mp_msg(MSGT_CPLAYER, MSGL_INFO,
+                   "...failed (need --vf=screenshot?)\n");
         }
     }
 }
@@ -363,13 +337,6 @@ void screenshot_flip(struct MPContext *mpctx)
     if (!ctx->each_frame)
         return;
 
-    // screenshot_flip is called when the VO presents a new frame. vf_screenshot
-    // can behave completely different (consider filters inserted between
-    // vf_screenshot and vf_vo, that add or remove frames), so handle this case
-    // somewhere else.
-    if (ctx->using_vf_screenshot)
-        return;
-
     ctx->each_frame = false;
     screenshot_request(mpctx, ctx->mode, true);
 }